1. Field of the Invention
The present invention relates to a library apparatus comprising a plurality of cells each for storing a cartridge containing a storage medium.
A library apparatus comprises a plurality of cells each for storing a cartridge containing an information storage medium such as a magnetic tape cartridge or an optical disk cartridge. A cartridge selected from one of the cells is loaded in the drive unit in the library unit. Information is recorded or reproduced into or from the medium contained in the cartridge by the drive unit.
Especially in recent years, a demand has been rising for a library apparatus of a large capacity used for searching a large amount of data for multimedia and graphics applications. A library apparatus is required to have a large capacity capable of containing as many cartridges as possible in a small installation space.
2. Description of the Invention
A library apparatus such as a magnetic table library apparatus is used for data search requiring a large capacity and comprises a plurality of cells each for storing a cartridge containing a storage medium. This library apparatus comprises a reference cell unit arranged at the central portion of the library apparatus, an accessor unit arranged at least at a longitudinal end of the library apparatus, a passage unit arranged between the reference cell unit and the accessor unit, a drum unit arranged at least on one side of the passage unit and including a plurality of cells each for housing a cartridge containing the storage medium, a drive unit arranged at least on one side of the reference cell unit for recording and reproducing the information in the storage medium contained in each cartridge, a guide rail arranged through the reference cell unit, the accessor unit and the passage unit, and an accessor arranged in the accessor unit to move along the guide rail for transferring the cartridge between a cell in the drum unit and a cell in the drive unit.
In this library apparatus, the accessor transfers the cartridge between a cell in the drum unit and a cell in the drive unit. The cartridge taken out of a given cell, however, must be accurately inserted into the intended cell by the accessor.
In the library apparatus, a higher mechanical accuracy of each unit makes it possible to insert the cartridge carried by the accessor into an intended cell with a higher accuracy. An increase in mechanical accuracy of each unit, however, requires a correspondingly higher processing accuracy and an increased manufacturing cost, thereby leading to the problem of a higher cost of the library apparatus.